Understanding Windows 7 Compatibility Issues

Any discussion of PC compatibility, of course, encompasses two very different but related topics: hardware and software. In order for a given hardware device—a printer, graphics card, or whatever—to work correctly with Windows 7, it needs a working driver. In many cases, drivers designed for older versions of Windows will actually work just fine in Windows 7. However, depending on the class (or type) of device, many hardware devices need a new Windows 7–specific driver to function properly on Microsoft’s latest operating system.

Software offers similar challenges. While Windows 7 is largely compatible with the 32-bit software applications that Windows users have enjoyed for over a decade, some applications— and indeed, entire application classes, such as security software—simply won’t work properly in Windows 7. Some applications can be made to work using Windows 7’s built-in compatibility modes, as discussed below. Some can’t. Those that can’t—like legacy 16-bit software or custom software typically found in small businesses—might be able to find solace in the new XP Mode feature in Windows 7.

A final compatibility issue that shouldn’t be overlooked is one raised by the ongoing migration to 64-bit (x64) computing. Virtually every single PC sold today does, in fact, include a 64-bit x64-compatible microprocessor, which means it is capable of running 64-bit versions of Windows 7. However, until Windows 7, virtually all copies of Windows sold were the more mainstream 32-bit versions of the system. We’ll explain why this is so and how the situation is now changing in favor of 64-bit with Windows 7.

From a functional standpoint, x64 and 32-bit versions of Windows 7 are almost identical. The biggest difference is RAM support: while 32-bit versions of Windows “support” up to 4GB of RAM, the truth is, they can’t access much more than 3.1GB or 3.2GB of RAM because of the underlying architecture of Windows. 64-bit versions of Windows 7, meanwhile, can access up to a whopping 192GB of RAM, depending on which version you get.